Crack in supply line at pitiless adapter....

Hello all! Recently purchased a home in rural Missouri. With the recent drought conditions apparently things have started shifting a little under ground. I noticed, in my otherwise sea of dead grass, fresh green growing directly under my well head on the side that the supply line leads directly to the house. Ground moist, etc, etc. No negligible loss of pressure after 10 hours of letting system pump to 50. Knew there had to be a leak, so I dug.
I've discovered that the black plastic supply line from the well into the basement is run THROUGH galvanized pipe to approximately one foot(possibly 16") shy of the brass pitless adapter output on the casing. Supply line plugs directly into pitless nipple, and secured with two stainless hose clamps. Found that the supply line is cracked at the hose clamp toward the end of said nipple(due to slight shifting), and was spraying pretty good until I loosened the clamp and put it over the crack. Now it's at a slow drip. Bearing in mind that I really don't want to be digging a 4ft deep 3ft wide hole In my yard again any time soon....what would a pro do to this that would be a permanent fix? Pull the supply line back through the galvanized pipe and put in new? Is there some type of more flexible piece to scab in? I can provide pix tomorrow. Age of system is unknown, I DO KNOW it's a submersible pump, 220v 3 wire. what do I backfill with (gravel/sand)? The galvanized runs directly through basement wall, by the way, carrying the black plastic pipe within. Thanks to all for the help.